This invention relates generally to hinges and more specifically to pin type hinge joints for large deployable space structures and has for its primary purpose the elimination of all post-deployment free-play in the hinge joints of such space structures and to provide a low resistance path for thermal and electrical conductivity across these joints.
There are numerous examples of hinged joints in the prior art as shown, for example, in the U.S. Pat. No. 2,991,102 to Vanwersch et al., for connecting beams of a roof support, the U.S. Pat. No. 4,286,353 to Roche for connecting structural member to prevent accidental collapse thereof, and more complex hinges are shown in the U.S. Pat. No. 3,599,164 to Ottersdorf.
All of these patented hinges completely ignore the problem of eliminating free-play in any structures let alone providing low resistance path for thermal and electrical conductivity. This is, of course, to be expected since none of the patents were involved in the deployment of space structures, etc., and did not address the problem that arose where finite clearances in pin joints, required to allow free rotation of the joint, precluded good electrical and thermal conductivity throughout the structure, nor did they address the problem of an accumulation of thousands of these finite clearances which would create significant free displacement of the structure at the extremities, upon depolyment.
It would seem that, if anything, the prior art tended toward more complex, more expensive, heavier hinge joints rather than toward simpler, less expensive and lighter hinge joints, which is the primary purpose of this invention.
Stated another way, advantages of this simple wedged butt joint are as follows:
a. lightweight because the size of the joint is minimized and additional material for bonding straps and precision bearings is not required; PA1 b. low cost because of its conventional manufacturing techniques, normal pin hole tolerances and use of less material; and PA1 c. simple maintainability because standard easily removed bolts are used for hinge pins.